Time switch



Patented Feb. 12, 1952 UNITED STATES PATENT OFFICE TIME SWITCH Application October 25, 1947, Serial No. 782,168

Claims. (Ol. 20o-39) Our invention relates to time switches and is particularly directed to improved means for pre-- selecting sequentially actuated electrical circuits.

In automatic washing machines, for example, it is possible to soak clothes, wash with soap, rinse in cold, hot or tempered water, and dry by centrifugal extraction. Solenoid valves are employed to admit water to and drain water from the tub. All of these various steps in the laundering cycle are conveniently electrically controlled and may be sequentially initiated by a motor driven commutator switch. It is desirable, in such a system, to preselect a particular step in the cycle of operations with which the cycle is to begin and end. Whether the time switch contemplated here is used to control an automatic washing machine or any other machine requiring sequential opening and closing of circuits, it is important that the rotor of the switch be advanced quickly to the desired starting point and that none of the interirn circuits be closed or actuated during the rapid advance. It is important, too, that the preselection of the starting point in the cycle be easily and accurately made, it being recognized that push-buttons may be selected and operated by feel, as distinguished from sight generally required for dials.

Objects of our invention include the provision of an improved time switch for sequential operation of a plurality of electric circuits; a sequential time switch which can easily and accurately be set to operate at any preselected step in a cycle of operations; and a sequential time switch which can be pre-set with push-buttons and which will not prematurely actuate any of the controlled circuits.

Our invention is particularly defined in the appended claims and one embodiment thereof is described in the following specification and shown in the accompanying drawings, in which:

Fig. 1 is a view in plan of the switch unit showing one arrangement of push-buttons that may be made in accordance with our invention;

Fig. 2 is a view in section taken substantially along line 2--2 of Fig. 1;

Fig. 3 is a sectional view similar to Fig. 2 with one of the push-buttons in actuated position;

Fig. 4 is a view in section taken substantially along line 4-4 of Fig. 2; and

Fig. 5 is a view in section taken substantially along line 5-5 of Fig. 2.

The several circuits to be controlled are opened and closed by a disc-type cam l with multi-level arcuate segments IA for `moving the cam followers 2 and attached electric contacts 3, into or out 2 of engagement with stationary contacts 4. The cam disc is keyed to the rotatable and slidable shaft 5. The contacts may be connected in the primary circuits of, in case of a washing machine, an agitator motor, a speed change solenoid, hot and cold water valve solenoids, and a drain valve solenoid. As the disc rotates, the several circuits.

are successively closed, the length of the cam segments and the cam speed being designed so that, preferably, one complete cycle of circuit operation may be completed in one revolution of the disc. For rapid opening and closing of the contacts the disc should be advanced step-by-step, a convenf tional synchronous clock motor 6 and escapement mechanism 1 being well adapted for such a movement. The escapement mechanism drives the shaft 5 through pinion 8 and gear 9. The frequency and amount of disc movement can, of course, be independently selected. y

Some commercial electric clock assemblies have a constant relatively high speed shaft and pinion outside the clock motor housing as shown at I0, in addition to the escapement pinion. We contemplate driving the disc at the higher speed to quickly bring the disc to the rotational position corresponding to the preselected starting operation of the cycle of operations. The usual commercial electric clock motor, unfortunately, lacks the power to drive a commutator of the type shown at the requisite high speed, the frictional drag of the several cam followers being considerable.

The mechanism now to be described moves the disc away from the followers to eliminate the drag, and at the same time shifts the disc drive from the slow to the fast pinions. Gear Il on the shaft meshes with pinion lli as the shaft moves down to disengage gear 9. Disengagement of the disc cam from its followers have the further function, as will now appear, of preventing operation of the cam actuated contacts during the preselection run of the disc.

The housing for our switch mechanism may be rectangular as shown with end plates l2 and I3 and with a transverse fixed center plate Il! about midway between the end plates. The shaft to which the dise is keyed passes through aligned holes in the three plates and is free to rotate and to slide lengthwise in the holes. A coil spring i5 is compressed between the center plate and the collar i6 on the shaft to bias the shaft upward. as viewed in Figs. 2 and 3. Hence, the gear 9 on the shaft is normally held in engagement with the escapement pinion 8.

Riding upon the collar I6 is a stiff light weight disc I'I which we call a wobble plate. The under side of the wobble plate bears at the center against the collar I6 while the other side rises against off-sets or shoulders I8 on the push rods I9 of a plurality of sequence selection elements shown here, for example, as push-buttons 20 arranged along the periphery of the wobble plate. When any one of the selector buttons is pressed, the wobble plate will tilt or pivot about a diametrically opposite push rod shoulder and will move the shaft 5 downward against the spring I5 and carry the gears 9 and I I from slow speed driving connection at 8 to high speed driving connection at IU.

Now, the shaft 5 may be held in its lower position and driven at the higher speed until the disc reaches the rotary position called for by the actuated push-button. Conveniently, the rods I9 may be stamped as single units from sheet metal, or wire stock, or if preferred, fabricated from two pieces as shown. The upper and lower legs of the push-rods slide freely through oiset slots in the end and center' plates I3 and I4, respectively. A spring 2I on each lower leg, is compressed between the center plate and a pin 2IA in the lower leg to bias the push 'od assemblies against the upper end plate of the housing. The shaft spring I5 in turn holds the wobble plate against the lower side of the oisets I8 of the rods. in the edge of each lower leg. As a push-button is pressed against the tension of the spring on the lower leg, the notched edge thereof is latched with the edge of the corresponding slot in the center plate so that the notch catches and holds on to the center plate when the button is fully actuated. The pressing and latch- *ing of one side of the wobble plate thus locks the gear II in mesh with the high speed pinion I as indicated in Fig. 3. The normal distance l between the notch and center plate is adjusted so that when latched, the cam disc will move out of contact with the cam followers.

To stop the high speed rotation of the cam disc in the position selected by the push-button, we key the radially extending release arm 23 to the shaft just below the center plate I4. The release arm sweeps across the lower ends of the push rods until it encounters the edge of a depressed push rod. Thereupon, the release arm disengages the notch on the push rod from the center plate, the push rod and shaft snap back t0 normal position, the shaft gear 8 shifts to the escapement pinion 8, the disc I engages the cam followers 2 and 2a, and the circuits, called for by the particular button which has been depressed, are closed commencing the desired cycle of operations.

Labels may be provided adjacent each pushbutton or as indicated in Fig. l each button may be suitably labelled and an index 24 is mounted on the end of the shaft for indication of the actuated push-button and thereafter, the label designating the operation being performed, the index being stepped around with shaft 5 as the sequence of operation proceeds.

In a time switch according to our invention, particularly for control of an automatic washing machine, good results may be obtained with a synchronous clock motor of known type having a second escapement. The pinion 8 and shaft gear 9 may have a-rato of 9-to-1 so as to move the disc I through 5 degrees each escapement. The pinion IU and shaft gear II may have a ratio of 1to1 and with such a A notch 22 is provided 4 speed as to drive the disc I through a full revolution in 8 to 15 seconds. The fact that the low power of the clock motor could drive the cam at this high speed is attributable to the elimination of the majority of frictional drag when the high speed gears were engaged.

The time switch of our invention can easily and accurately be setto operate at any preselected step in a cycle of circuit sequences, is simple and particularly inexpensive in construction, and has the advantages of push-button operation.

We claim:

1. A timeswitch comprising a plurality of sequence selection elements each representing an operation in a given sequence of operations, switch contacts forcontrol of said operations, timer means for actuating said contacts in sequence, and means responsive to actuation of a sequence selection element to bring said timer means into asta'rting positionccrresponding to the lpoint in said sequence corresponding to thc operation representedby the actuated' sequence selection element, including means to render said timer means inoperative with respect to control of said operations while said timer means is being brought to said starting position.

2. A time switch according to claim 1 wherein the means responsive to actuation of a sequence selection element includes means for causing said timer means to operate at a speed higher ythan the sequence operation speed for rapid advancement of said timer means to a selected point in said sequence.

3. A time switch according to claim 1, wherein said timer means includes a normal sequence operation speed and a high speed operation for rapid advancement toga point in said sequence corresponding to an actuated sequence selection element. and said means responsive to actuation of such an element causes said timer means to operate atv said high speed, until the point in said sequence corresponding to the element actuated is reached, and then to cause said timer means to operate at normal speed for sequence operation.

4. A time switch according to claim l, wherein said sequence selection elements comprise push buttons and each push button includes means movable into the path of said timer means for initiating a sequence of operation when said timer means reached the location of the actuated push button.

5. A time switch according to claim l, wherein said sequence selection elements comprise push buttons, each push button having means for latching the push button in actuated position, said timer means having a member movable past the locations of said push buttons to release any latched push button when reached, the release of the last latched `push button operating to initiate a sequence of operation starting with the operation represented by such last released push button.

6. A time switch according to claim 5 wherein said timer means includes high and lower speed drives and means responsive to the actuation of a push button to drive said member according to said high speed until said member releases the last latched push button in said sequence, the releasing of such push button operating to shift the drive of said member to said low speed.

7. A time switch according to claim l wherein said timer means includes a cam and a follower for actuation of said contacts, and said responsive means is operative to separate said cam and follower during operation of said timer during its advancement to the point in said sequence corresponding to the operation represented by an actuated sequence selection element.

8. A time switch according to claim 1 wherein said sequence selection elements comprise push buttons and said timer means includes a member movable past the location of said push buttons for engagement with any actuated push button, a high and a low speed drive for said member, and said responsive means is responsive to the actuation of a push button to release the low speed drive with respect to said member and to connect the high speed drive with respect to said member, said timer means further including a cam and follower for actuation of said switch contacts in sequence, said responsive means operating to separate said cam and follower and means responsive to engagement of an actuated push button by said member to return said member from said high speed to said low speed drive and to cause said cam and follower to re-engage.

9. A time switch comprising a shaft, low and high speed driving connections for said shaft, means driven by said shaft to actuate said contacts, means to urge said shaft to a position for coaction with said low speed driving connection and for actuation of said contacts, a wobble plate centrally mounted on said shaft, said sequence if selection elements comprising push vbuttons having offsets for engagement with said wobble plate adjacent the periphery thereof whereby the actuation of a push button pivots said wobble plate about a point adjacent the periphery thereof to move said shaft axially for disengagement from said low speed driving connection and to render inoperative .the means for actuating said contacts and to make engagement with said high speed driving connection, means for latchw ing an actuating push button and a member carried by said shaft adapted to release an actuated push button from latched position whereby the wobble plate releases said shaft for disengagement with said high speed driving connection and re-engagement with said low speed driving connection.

10. A time switch comprising a disc type cam, a plurality of cam followers riding on one face of the cam, a shaft extending centrally through and keyed to said cam, a high speed drive, a low speed drive, and means .to shift said shaft for selective co-action with one or the other of said high and low speed drives, said shaft when shifted to one drive position effects disengagement of said cam and said followers.

11. A time switch comprising a cam with cam follower, a shaft extending centrally through and keyed to said cam, means for driving said shaft operatively connected thereto, a plurality of push buttons with push rods arranged circumferentially of said shaft with the rods of said push rods disposed parallel to said shaft, an arm keyed to and extending radially from said shaft and arranged to sweep by the ends of said push rods, said push rods being selectively movable by said push buttons into the path of said arm.

12. A time switch comprising a disc, cam segments on one face of said disc, a cam follower riding on said cam segments, electric contacts responsive to movement of said follower, a motor driven rotatable shaft, said disc xed to said shaft, a plurality of push rods parallel to and circularly arranged around said shaft, a catch on each rod for latching each rod in depressed position, a radially extending arm fixed on said shaft and engageable with any depressed rod to unlatch said depressed rod, and means responsive to unlatched movement of said depressed rod for effecting a change in the speed of rotation of said shaft.

13. A time switch comprising a disc, cam segments on one face of said disc, cam followers respeotively associated with said cam segments, a motor, a high speed pinion and a low speed pinion associated with said motor, a shaft carrying said disc, gears on said shaft selectively engageable with said respective pinicns, a plurality of push buttons, means for mechanically linking each push button and said shaft for selectively shifting said gears into mesh with said high speed pinion and said low speed pinions respectively.

14. In the time switch defined in claim 13, an escapement mechanism, said mechanism being connected between said motor and said low speed pinion for imparting step-by-step movement to said low speed pinion.

15. A time switch comprising a rotatable shaft, electric contacts, means operatively connecting said contacts to said shaft for actuation thereby, a plurality of push-rods symmetrically arranged around and parallel to said shaft, each push rod having a right-angle olf-set, the off-sets of the rods being disposed in a common plane normal to said shaft, a push button on one end of each push rod, a notch in the other end of each push rod, a fixed plate transversely of said push rods with slots receiving said other ends of the push rods and engageable with the notch of any depressed push rod, a movable plate transversely of said push rods and pressed between said off sets and a collar on said shaft, and a radially extending release arm carried by said shaft to sweep past the ends of said push rods and to effect a disengagement between said fixed plate and said notch.

MORTON A. KREITCHMAN. JAMES H. TANNER.

REFERENCES CITED The following-references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 484,360 Gawley Oct. 11, 1892 1,475,111 Gries et al Nov. 20, 1923 1,520,233 Gabriel Dec. 23, 1924 1,522,696 Nosal Jan. 13, 1925 1,785,736 Hess Dec. 23, 1930 2,096,620 Robertson Oct. 19, 1937 2,276,445 Young Mar. 17, 1942 2,289,475 Anders July 14, 1942 2,391,718 Lindeman Dec. 25, 1945 2,475,311 Daly July 5, 1949 

